Lifting attachment for industrial trucks



H. 4. s MlTH EI'AL LIFTING ATTACHMENT FOR INDUSTRIAL TRUCKS Jan. 4, 1955 Filed Sept. 22, 1951i .III IQI INVENTQRS -Harold.

Smith. H

United States Patent LIFTING ATTACHMENT FOR INDUSTRIAL TRUCKS Harold J. Smith and Casper H. Uldriks, Battle Creek, Mich., assignors to Kellogg Company, Battle Creek, Mich., a corporation of Delaware Application September 22, 1952, Serial No. 310,882

1 Claim. (Cl. 214-620) This invention relates to fork-lift industrial trucks, and more particularly to a lifting attachment for trucks of this type.

In the use of fork-lift industrial trucks for transporting material to various parts of a plant, the material is usually supported upon pallets designed to permit insertion and withdrawal of the fork during engagement and disengagement of the fork under the pallet.

In the use of fork-lift trucks for transporting material which is not supported upon a pallet, the material is usually manually loaded upon and removed from the fork. Some industrial trucks are, however, provided with hydraulic pusher devices operative to push a load of material from its loaded position on the fork onto a pallet, floor or other form of support. As these pusher devices are expensive, bulky, and sometimes become inoperative, the present invention contemplates the provision of a lifting attachment which permits material be unloaded therefrom without the use of a pusher CVICC.

This invention further contemplates the provision of a lifting attachment adapted to be secured to the lifting carriage of an industrial truck and embodying a set of fork members for use in lifting material loaded on conventional pallets, and another set of fork members employed for lifting material in bags.

This invention further contemplates the provision of a lifting attachment in which the bag lifting fork members are arranged in fixed position on the lifting carriage of the truck, while the pallet engaging form members are pivotally mounted on the lifting carriage for movement from an operative position to an inoperative positton.

A further object of this invention is to provide a lifting attachment in which the bag lifting fork members are preferably formed of round rod stock to permit withdrawal of the members from under a load of bagged material by merely moving the truck away from the material.

This invention embodies other novel features, details of construction and arrangement of parts which are hereinafter set forth in the specification and claim and illustrated in the accompanying drawing, wherein:

Fig. 1 is a perspective view illustrating a lifting attachment embodying features of the present invention, the attachment being shown as applied to a power actuated lift carriage of an industrial truck.

Fig. 2 is a perspective view illustrating the lifting attachment, showing the pallet lifting forks secured in their upright position by means of latches.

The lifting attachment is shown as comprising a generally rectangular frame 2 embodying spaced side members 4-4, a top member 6 and a base member 7. A transverse member 9 extends between the side members 4-4 above the base member 7, and a central upright member 11 extends between the top and base members. A pair of spaced fork housing members 12-12 are spaced inwardly from each side member 4 and extend between the top and base members. The several parts of the frame 2 thus shown and described are welded together to form a sturdy structure capable of supporting relatively heavy loads.

The base member 7 is provided at spaced intervals with forwardly projecting mounting brackets 13 formed with cylindrical bores to snugly receive the ends of bag lifting fork members 14 formed of rod stock, the mem- 2,698,698 Patented Jan. 4, 1955 bers being welded or otherwise secured to their respective brackets and provided with rounded ends and smooth surfaces to oner mm1mum frictional resistance to withdrawal of said members from underneath a stack of material contained in bags.

A pair or pallet lirtmg fork members 16 of generally rectangular cross section having a greater width than thickness are each provided WllIl a pair of spaced, upwaruly pro ecting bearing ears 17-1! formed with coaxial apertures to receive a pivot pin 16 mounted at its ends in the fork housing members 12-42. lt' desired, the fork members .to may be of hollow construction and formed with wedge-shape front ends 19.

The pivotally connected ends or the form members 16 are disposed in abutting engagement with the base member 7 when the fork members are in operative lilting position in a plane normal to the frame 2. When the pallet engaging fork members 16 are pivoted to their inoperative position, their tree ends are engaged by latch members 21 pivotally mounted on the frame 2. When the fork members 16 are manually pivoted to their inoperative position, their respective latch members 21 are rormed and balanced to automatically engage the free ends of the fork members to secure the latter in lixed position in a common plane with the frame 2.

The lifting attachment is adapted to be permanently or detachaoly connected to a carriage 2'6 01' a conventional industrial truck 24 by means of rivets or bolts extending through the base member 7 and transverse member 9, the carriage being movable vertically along upright guides 26-26 of the truck by conventional power means (not shown) under the control of the operator.

in the use of the lifting attachment on industrial trucks in lilting, transporting, and removing material contained in bags, the pallet llrting forks 16 are lirst pivoted to their inoperative position with their upper ends engaged by their respective latches 21. The bags of material are then manually stacked upon the bag lifting forks 14 and raised above the floor by the power operated carriage 23 of the truck 24 for transportation to a different part of a plant.

In removing the bags from the truck, the carriage 23 is lowered until the bags engage and come to rest upon a floor, pallet, stacked bags, or other support; after which the truck 24 is moved rearwardly to withdraw the bag lifting forks 14 from underneath the load of bags. Due to the relatively wide spacing between the forks 14 and also due to the smooth, small-diameter cylindrical surfaces of the forks, it is possible to withdraw the forks from underneath a load of material in bags without imparting corresponding movement of the bags along their support, due to relatively greater frictional resistance between the load and support than between the load and the forks. It is thus possible to unload bags of material from forks without employing hydraulic pushers or the like to push the load from the forks.

When the truck is employed in moving material supported on conventional pallets, the pallet lifting forks 16 are pivoted to their operative position between the forks 14 for movement into engagement against the underside of the pallet in a manner well known in this art for lifting, transporting, and unloading the pallet.

While this invention has been shown in but one form, it is obvious to those skilled in this art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit and scope of the claimed invention.

We claim as our invention:

In a lifting attachment to be secured on a lift carriage of an industrial truck, a fabricated rectangular shape frame including connected top, bottom and upright side members, five forks arranged in spaced parallel relation secured to said base member and projecting outwardly therefrom in a plane normal thereto, two of said forks having flat upper surfaces in a common plane with the upper surfaces of the other of said forks, said other forks being formed of round rod stock, said two forks being movable to an upright position against the front side of said frame to permit bags of material loaded onto the other of said forks to sag downwardly into frictional engagement with a load supporting surface to permit withdrawal of the forks from underneath the load, latch means to secure said two forks in an upright position, and means to secure said frame to a lift carriage of a truck.

References Cited in the file of this patent UNITED STATES PATENTS Ryerson Dec. 8, 1931 Chubb et a1. July 26, 1932 Flynn et al. July 20, 1948 Cushman Jan. 8, 1952 Hally Feb. 5, 1952 Le Tourneau Mar. 11, 1952 Feb. 17, 1953 Sutherland Mar. 31, 1953 

